Sharp freezer



Jan. 26, 1926.

C. E. L. LIPMAN SHARP FREEZER Filed August 20 1923 I I- .7 I 1.

Patented Jan. 26, 1926.

UNITED STATES CARL E. L. LIPMAN, OF IBELOIT, WISCONSIN, ASSIGNOB TO LIP MAN REFRIGERATOR PATENT OFFICE.

CAB & MANUFACTURING COMPANY, OF IBELOIT, WISCONSIN, A CORPORATION OF DELAWARE.

snanr FREEZER.

Application filed August 20, 1923. Serial No. 658,216.

To all whom it may concern:

Be itknown that I, CARL E. L. LIPMAN, acitizen of the United States, residing at Beloit, in the county of Rock and State of Wisconsin, have invented certain new and useful Improvements in Shar Freezers, of i which the following is a speci cation.

This invent-ion pertains to refrigerating apparatus,-and is shown herein for illustratlve purposes as applied to that portion of theapparatus which is adapted for freezing ice cubes and maintaining the same in frozen condition.

In household and other small refrigerating apparatus, it is desirable to freeze a small quantity of ice in addition to maintaining the cooling compartment, in which the food products and the like are stored, at

a predetermined temperature. It has heretofore been proposed to-introduce one or --more small trays containing water to be frozen into the interior of the expansion or cooling coils of the refrigerating system,

where these trays were subjected to the minimum temperature produced by the appara-- tus. The trays, however, were exposed, and their temperature would be afiected by the inrush of warm air each time the door of the cooling compartment was opened. Under these conditions, it has in many instances become practically impossible to maintain the water in the trays in frozen condition. The primary purpose of m present invention is to provide a meta lic chamber, termed a sharp freezer, in which the ice trays or other objects or materials to be cooled are positioned. The walls of the chamber are preferably formed of relatively thick cast-iron, which serves to prevent any 40 rapid fluctuations of temperature within the chamber,'with the result that a rise in temperature in the cooling compartment sur rounding the chamber caused by the opening of the door, will not immediately affect the temperature within the sharp freezer. The

ice which has been frozen in the trays or any other substance in the chamber can therefore be maintained in frozen condition;

and furthermore, due to the concentration of the refrigerating action in the sharp freezer, a lower temperature can be produced and maintained within the freezer than is possible if the cast metal walls surrounding the ice trays be dispensed with.

For the purpose of facilitating an understanding of my invention, I have illustrated on the accompanying drawings a preferred embodiment thereon-"referring to which,

Fig. 1 is a fragmentary front elevation of a refrigerating apparatus embodying my invention; and

Fig. 2 is an enlarged elevation, partially in section, of the sharp freezer.

Referring to the drawings more in detail, reference character 3 indicates generally a refrigerator of well known or preferred construction, providing the usual cooling compartment or compartments in which the articles to be preserved are stored, and a compartment 41 in which the expansion or cooling coils, indicated generally by reference character 5, are disposed.

The refrigerating machine may be of any preferred construction, the type illustrated comprising a compressor 6, operated from a motor 7, and a condenser 8, from which the condensed refrigerating medium, which may be ammonia, CO, or other suitable refrigerant, is conveyed through the pipe 9 to the expansion valve 11. 7

From the expansion valve, the refrigerating medium, which has passed the valve, is conducted through a pipe 12, coiled to pro vide a horizontally disposed coil 13 and a vertically disposed coil 14, these coils constituting the expansion or refrigerating coils through which the heat units from the cooling compartment are absorbed by the refrigcrating medium within the coils.

The coil 13 comprises a number of convolutions surrounding and embracing a relatively thick walled metal shell 15, forming a chamber in which the ice trays 16 or other articles are rem'ovably disposed. This shell is preferably made of cast metal, the heat conductivity of which -is suchthat when the interior thereof has become thoroughly cooled, a considerable lapse of time will be required to materially raise its temperature, even though the temperature of the sur rounding air in the cooling compartment is relatively high. The front of the shell may be closed by a cast-iron door 17, which may be opened to permit access to the interior of the chamber for the insertion and removal of the ice trays.

By reason of the fact that this shell is surrounded and embraced by the expansion coil 13, with the result that the interior of the shell may be reduced to and maintained at a very low temperature, the construction is termed a sharp freezer, and may be employed for the production of ice cubes which may be quickly frozen in the trays 16. By reason of the fact that the chamber in which these trays are disposed is entirely enclosed by heavy cast-metal walls, the trays are not subjected to sudden changes of temperature resulting from the opening of the doors of the cooling compartment, and consequently the ice formed in the trays is not melted, even though the doors of the cooling com partment may be open for some time. The sharp freezer acts, therefore, as a storage reservoir to maintain a low temperature, and temperature fluctuations in the chamber are very much less than the fluctuations in the surrounding cooling compartment.

It will be apparent that the sharp freezer precludes rapid temperature fluctuations upon its interior, and enables the production and maintenance of extremely low temperatures in the freezer. It should be understood, however, that. the principles of the invention may be employed in various apparatus where the maintenance of low temperatures is desirable, as for instance, in

ice cream storage and dispensing cabinets where the ice cream containing compartments may be constructed in accordance with the principles of my invention. The details of construction illustrated and described are of course capable of considerable modification within the scope of the invention, as defined in the following claims.

I claim:

1. A refrigerating apparatus including a refrigerating chamber and a sharp freezer therein, said sharp freezer comprising a refrigerating coil and a chamber surrounded by the convolntions of said coil, the walls of said chamber being formed of thick metal adapted to materially retard the transference of heat units therethrough. 1

2. In a refrigerating apparatus the combination of a thick walled compartment formed of cast metal adapted to materially retard temperature fluctuations within the compartment, and a refrigerating coil surrounding the perimeter of said compartment.

3. A refrigerating apparatus including a refrigerating chamber and a shar freezer therein, said sharp freezer comprising a refrigerating coil and a chamber surrounded by the convolutions of said coil, the walls of said sharp freezer chamber being formed of thick cast metal possessing the characteris tics of low heat conductivity and high thermal capacity, to thereby prevent rapid fiuc tuations of temperature within said sharp freezer chamber upon a rise of temperature within said refrigerating chamber.

4:. A refrigerating apparatus, including a cooling compartment and a sharp freezer therein, said sharp freezer comprising a refrigerating coil and a chamber surrounded by the convolutions of said coil, the walls of said chamber being formed of thick cast metal possessing the characteristics of low 'heat conductivity and high thermal capacity, and a movable door for said chamber, said chamber walls being adapted to prevent rapid fluctuations of temperature within said chamber when there is a rise in temperature in the cooling compartment.

CARL 'E. L. LIPMAN. 

